P0119 OBD-II Trouble Code: ECT Sensor Circuit Intermittent Malfunction Problem

P0119 code definition

Engine Coolant Temperature (ECT) sensor circuit intermittent malfunction problem.

What the P0119 code means

P0119 is the generic OBD-II code which indicates that the Engine Control Module (ECM) has detected intermittent ECT sensor input.

What causes the P0119 code?

The ECT sensor input to the ECM is erratic; not giving a steady, stable reading.

What are the symptoms of the P0119 code?

• The ECM turns on the Check Engine Light and goes into failsafe mode, substituting input to 176 deg F.

• The engine may have a hard start when the engine is cold, and will start normal when warm.

• The engine may run rough and hesitate until the engine warms up.

• The engine should run close to normal once the engine warms up.

• Since the ECT input is intermittent, the ECM may go in and out of failsafe mode, causing the engine to run erratically.

Note: The symptoms are determined by the manufacturer failsafe ECM strategy for the vehicle during a failure and may vary between manufacturers and vehicles.

How does a mechanic diagnose the P0119 code?

• Visually checks to see if coolant is full, and that the system and thermostat are working correctly

• Scans and documents the codes that are received and views the freeze frame data to see when the code was set

• Clears the OBD-II fault codes and retests the vehicle to see if the code comes back

• Observes the sensor’s live data on the scanner to ensure that the temperature output is within specifications while wiggling the sensor connector and wiring

If no problems are noted, then the next step for the technician is to disconnect and check the sensor and connector for problems like corrosion or loose connections. Corroded sensors and connectors should be replaced.

Common mistakes when diagnosing the P0119 code

• Not performing a visual inspection regularly

• Not following the manufacturer's pinpoint test procedure step-by-step or skipping steps

• Not replacing an ECT sensor when tests indicate a problem

• Not trying to connect and view the ECM data to see if the temperature output from the sensor is as expected before installation of the new ECT sensor

How serious is the P0119 code?

• The ECM may go in and out of failsafe mode since the problem is intermittent.

• The problem may progress to a more permanent or serious failure if problem is not repaired.

• Intermittent failure may be shorted wiring that could damage the ECM or wiring.

What repairs can fix the P0119 code?

• Testing and replacing any other ECT sensor codes first
• Repairing or replacing the ECT connector
• Repairing or replacing an open wire or short as necessary
• Replace the ECT with a new sensor
• Replace the ECM if shorted out

Additional comments for consideration regarding the P0119 code

• The P0119 code is often associated with P0115, P0116, P0117 and P0118 codes.
• Most failures for code P0119 include a harness shorting, or a connector corrosion issue.

Need help with a P0119 code?

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